Twitter has blocked Flattr, a "payment" service in which people could get paid for having their tweets favourited by other users, from accessing its systems.

The move is the latest part of Twitter's strategy to build a wall around its revenues and prevent rival companies from leaching off any by diverting users - a policy that it has been following with growing intensity since its acquisition of Tweetdeck in May 2011.

Flattr describes itself as a "social microdonation service" which aims to "help creators get paid for their digital content". Users join Flattr, set up a monthly budget, and then click buttons - until now, including "favouriting" tweets on Twitter - to indicate their approval of content creators. At the end of each month, the budget is distributed among the recipients.

We think that we've created a beautiful way to support creators by checking what you favorited on Twitter and letting you send a flattr to the writer of a tweet. Twitter did not.

So we are extremely sad to announce that from today (16th of April 2013) at noon CET we will remove the possibility to flattr tweets via the use of favorites, as per instructions from Twitter.

Twitter, it said, had complained that that broke its API terms about "Advertising Around Twitter Content", which says:

"Your advertisements cannot resemble or reasonably be confused by users as a Tweet. For example, ads cannot have Tweet actions like follow, retweet, favorite, and reply. And you cannot sell or receive compensation for Tweet actions or the placement of Tweet actions on your Service."

Flattr needs an API key - in essence a password to Twitter's database - in order to provide the functionality around rewards for favourites. Without that, its task would be impossible, and Twitter was threatening to remove that authorisation.

But Olsson said that while the rule is logical to stop companies selling retweets and followers, he said that Flattr was willing to forgo its 10% commission on the donations. Twitter however turned that down too, telling him that "you cannot sell or receive compensation for Tweet actions or the placement of Tweet actions on your Service."

It added that "That includes compensation attached to a Tweet Action [such as a retweet or favoriting] sent to either a [third-party] service or through a service to another user.s"

Olsson complained "We feel that Twitter is reading things into their terms that is not there."